sigmamediumHunting

UAC Secure Desktop Prompt Disabled

Detects when an attacker tries to change User Account Control (UAC) elevation request destination via the "PromptOnSecureDesktop" value. The "PromptOnSecureDesktop" setting specifically determines whether UAC prompts are displayed on the secure desktop. The secure desktop is a separate desktop environment that's isolated from other processes running on the system. It's designed to prevent malicious software from intercepting or tampering with UAC prompts. When "PromptOnSecureDesktop" is set to 0, UAC prompts are displayed on the user's current desktop instead of the secure desktop. This reduces the level of security because it potentially exposes the prompts to manipulation by malicious software.

MITRE ATT&CK

T1548.002

privilege-escalationdefense-evasion

Detection Query

selection:
  TargetObject|contains: \Microsoft\Windows\CurrentVersion\Policies\System\PromptOnSecureDesktop
  Details: DWORD (0x00000000)
condition: selection

Author

frack113

Created

2024-05-10

Data Sources

windowsRegistry Set Events

Platforms

windows

References

https://github.com/redcanaryco/atomic-red-team/blob/7e11e9b79583545f208a6dc3fa062f2ed443d999/atomics/T1548.002/T1548.002.md

Tags

attack.privilege-escalationattack.defense-evasionattack.t1548.002

Raw Content

title: UAC Secure Desktop Prompt Disabled
id: 0d7ceeef-3539-4392-8953-3dc664912714
related:
    - id: c5f6a85d-b647-40f7-bbad-c10b66bab038
      type: similar
    - id: 48437c39-9e5f-47fb-af95-3d663c3f2919
      type: similar
status: test
description: |
    Detects when an attacker tries to change User Account Control (UAC) elevation request destination via the "PromptOnSecureDesktop" value.
    The "PromptOnSecureDesktop" setting specifically determines whether UAC prompts are displayed on the secure desktop. The secure desktop is a separate desktop environment that's isolated from other processes running on the system. It's designed to prevent malicious software from intercepting or tampering with UAC prompts.
    When "PromptOnSecureDesktop" is set to 0, UAC prompts are displayed on the user's current desktop instead of the secure desktop. This reduces the level of security because it potentially exposes the prompts to manipulation by malicious software.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/7e11e9b79583545f208a6dc3fa062f2ed443d999/atomics/T1548.002/T1548.002.md
author: frack113
date: 2024-05-10
tags:
    - attack.privilege-escalation
    - attack.defense-evasion
    - attack.t1548.002
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: '\Microsoft\Windows\CurrentVersion\Policies\System\PromptOnSecureDesktop'
        Details: 'DWORD (0x00000000)'
    condition: selection
falsepositives:
    - Unknown
level: medium